1. Technical Field
The present invention relates to an image reading device including an image forming optical device that forms an erect equal-magnification image by forming an image of reflected light from an object to be read.
2. Related Art
In the related art, a contact image sensor module (hereinafter, simply referred to as “CIS module”) is used as an image reading device in image scanners, facsimiles, copy machines, financial terminal devices, and the like. The CIS module includes an illumination unit that illuminates an object to be read, an image forming optical device that forms an erect equal-magnification image of the object to be read, and a sensor that reads the erect equal-magnification image formed by the image forming optical device. In the CIS module, reflected light from the object illuminated by the illumination unit is condensed by the image forming optical device, and thus the erect equal-magnification image is formed on the sensor. For example, in an image reading device disclosed in Japanese Patent No. 4,145,271 (paragraphs 0018 to 0024, FIG. 1, and the like), rod-shaped light guide bodies formed of a transparent member such as an acryl resin are accommodated in a case and are fixedly disposed respectively in concave portions that are disposed on the right and left sides of an upper surface of a housing, and a lens array (image forming optical device) is fixedly disposed in a through hole provided between the light guide bodies of the housing.
Incidentally, in the related art, since the light guide body and the image forming optical device are fixed to a predetermined position of a holding unit such as a housing an adhesive agent, it is difficult to remove and disassemble the light guide body and the image forming optical device from the holding unit when the image reading device is discarded, and thus a technique is required to be improved from the viewpoint of recycling efficiency.